Past snowmobiles have used liquid cooling systems to cool their internal combustion engines. Snowmobiles with these liquid-cooled engines often have auxiliary radiators or heat exchangers spaced away from the engine itself. In some of these snowmobiles, the radiators are positioned within the drive tunnel that is within the snowmobile chassis. The drive track, also disposed within the drive tunnel, carries and circulates snow within the drive tunnel as the track moves. The radiators are positioned adjacent the track so that some of the snow carried by the track will be thrown at the radiators to provide a heat exchange. The melting of snow requires a substantial amount of heat which is removed from the coolant circulated in the radiators.
Since space is limited, radiators often have a plurality of fins to improve the heat exchange without substantially increasing the size or number of the radiators. On snowmobiles with larger engines, though, using front and back radiators with fins may still not provide sufficient cooling.
Aside from circulating snow within the tunnel, the drive track in typical snowmobiles will throw snow onto the snowmobile's operator foot area. Since typical snowmobiles provide recessed footwells for a rider's feet, the snow kicked up by the track and by movement of the machine tends to accumulate in the recesses of the footwells. The accumulated snow not only adds undesirable weight to the machine, but it may also cause the rider's feet to slip from the snowmobile.
On other past snowmobiles, additional radiators are installed under the driver footrest area to melt accumulated snow. However, such additional radiators require additional space and add undesirable weight to the snowmobile.